I don't have the ability to tell apart a baby red-factor from a baby regular-sun. I am not sure whether it is even possible to do so, or not.
But, I can answer part of your question in a way, which is this:
A baby sun conure of any kind is gonna have a lot more green feathers mixed in, and as it gets older it will lose them gradually but entirely. At six months, when I got my (regular) sunny, people said to me ""are you sure this isn't a jenday or a hybrid?" So as this baby gets older it is (1) gonna be beautiful, because All sunnies are, and (2) be much brighter (whether orange or red I can't tell) with much less green.